Gummis

Gummis restore a varying amount of Belly, which also depends on type. See this page for more details.

Gummis are a special food item which raise a Pokémon's IQ when eaten; the different colors of Gummis affect Pokémon depending on their type(s). When the Gummi eaten matches the Pokémon's type, it gives the best IQ boost, 5 points (7 in Red Rescue Team and Blue Rescue Team). The amount of IQ gained depends on the type matchups if it doesn't match the Pokémon's type. In RB, however, these values are added together on dual-type Pokémon.